A floor plan with as much detail as possible ideally in standard measures only because the US users will have difficulty converting. Mark all windows doors and where the plumbing is.

you are working with what we call "freestanding pieces "...or unfitted . On the wall with the lightswitch I would measure and wrap cabinets, as we call them [furniture]…...from the window all the way to the light switch or, near the opening there. this issue of getting more counter and things working better together would be simple as you have a "galley". I do not know your budget...but I would take the measurements to a HOME STORE that has kitchen design and allow them to fill in the wall in question with cabinets and use the fridge and oven if you want to keep them. there is a jog or change , setback in the wall so working with depth issues with "fitted cabinets " will be to your benefit and running the counter into and beyond that "jog" will give you a more streamlined working kitchen. It all depends on your budget but you can do quite a bit to make a very good kitchen just by focusing on the lightswitch wall.

Thank you for the response. In principle it is a small addition, since most of the appliances are already there, but I don't have too much imagination...:). I like the ideas proposed, and will visit a store to get into action. Thanks!